sign in sign up
<<
Home , Banksia, Macadamia, Macadamia integrifolia, Macadamia jansenii, Macadamia ternifolia, Macadamia tetraphylla

integrifolia

There are seven Macadamia native to , with the Queensland nut tree being one of two species that have an edible nut. The attractive foliage and flowersM. integrifolia have made it a popular tree for domestic yards. It is also the species most commonly used for commercial production of nuts, although it is often crossed with other Macadamia species. Wild populations of M. integrifolia are rare and have a restricted and scattered distribution in Photo: CSIRO Industry rainforest throughout south-east Queensland from Bauple (about Description 30km south of Maryborough) in Macadamia integrifolia is a rainforest species endemic to Queensland. It is also known as the smooth-shelled macadamia, bush nut, nut oak, Queensland nut, Bauple nut or the north, south to Nicoll Scrub bopple nut. Macadamia species, like , and , are members of near the the . border. M. integrifolia is in M. integrifolia can grow to 20m in height with a similar foliage width, giving the tree a danger of becoming extinct in round shape. The trunk is rough but not furrowed, without buttress roots, and reaches a the wild due to extensive diameter of around 30cm. M. integrifolia are thick and leathery, growing to 14cm clearing of its rainforest habitat and arranged on branchlets in groups of three. Mature edges are smooth, but newly formed leaves have a spiny margin. are cream/white in colour on up to in south-east Queensland for 30cm in length that grow from the leaf axil and hang down from the branches. The green rural and urban development. leathery outer shell (also known as a pericarp or vessel) is around 2.5–3.5cm in size and surrounds a smooth brown nut-shell containing a white edible kernel. Flowering has been recorded from August to October, with fruiting from December to March. M. integrifolia is the most popular species used worldwide for commercial production of macadamia nuts. These commercial tree varieties are often smaller than naturally- growing species. Macadamia nut farmers have been selectively M. integrifolia with other Macadamia species (frequently M. tetraphylla) to increase desirable The macadamia nut is the commercial qualities such as a thinner shell, increased yield and disease resistance. only Australian native The National Macadamia Germplasm Conservation Program, an initiative of the produce that has achieved Commonwealth Scientific and Industrial Research Organisation (CSIRO) and the major commercial success. Australian macadamia industry, is establishing plantations of all wild varieties of Macadamia with the aim of having a stock gene pool to aid preservation of the species and provide readily available resources for commercial research. Queensland nut tree Macadamia integrifolia

Habitat and distribution M. integrifolia was originally associated with subtropical rainforest that was spread along a 600km coastal strip between Grafton in New South Wales and Maryborough in Queensland, extending up to 150km inland. Current distribution of wild M. integrifolia appears to be similar to the initial distribution area, however populations are more sparsely distributed, and overall numbers have declined as a result of agricultural and urban development. Although M. integrifolia is a rainforest species they tend to grow better in partially open areas such as rainforest edges. They can be found at elevations near sea level up to 600m, preferring well-drained sites on hill crests, hill slopes, scree slopes, foot slopes and along the edges of hoop pine cunninghamii scrubs and creek beds. M. integrifolia grows best in mild frost-free weather with reasonably high rainfall and has been recorded fruiting as far south as . At many sites where M. integrifolia occurs there are less than ten remaining. The largest populations are recorded in Amamoor State , Bahr’s Scrub, Nicoll Scrub and National Parks, and they also occur in several other national parks and state as well as three nature refuges. M. integrifolia grows in complex notophyll vine forest, simple notophyll vine forest and in simple microphyll-notophyll vine forest with emergent Araucaria and Argyrodendron species. It can be found in uniformly dark surface soils that vary in texture from clayey sand through various types of loam to silty clay.

Leaves, flowers and nuts ofMacadamia integrifolia. Photos: CSIRO Plant Industry

Naturally occurring Macadamia integrifolia have always been recorded in areas associated Distribution of Macadamia integrifolia in Queensland. Map: EPA with subtropical rainforest.

 Queensland nut tree Macadamia integrifolia

There are nine Macadamia species, seven of which are endemic to Australia, and two species (M. hildebrandii and M. erecta) that are native to the island of in Indonesia. The Australian native species can be divided into two distinct groups — the tropical species found in Far North Queensland (M. claudiensis, M. grandis and M. whelanii) and the subtropical species found in south-east Queensland (M. jansenii, M. integrifolia, M. tetraphylla and M. ternifolia). Distribution of the two edible species, M. integrifolia and M. tetraphylla, extends to northern New South Wales. Macadamia species in south-east Queensland

M. tetraphylla, also known as the M. ternifolia is similar in appearance M. jansenii is smaller than other rough-shelled nut, has a similar height to M. integrifolia and M. tetraphylla Macadamia species, reaching a and distribution to M. integrifolia. It can however it is a smaller tree, growing to height of 6–9m. First discovered in be distinguished by -purple flowers around 10m, and produces small nuts 1982, it is only known from an area and having leaves with spiked margins (around 2cm including outer green west of Miriam Vale in Queensland. that are arranged in groups of four on shell) that are bitter and slightly toxic. The inedible nuts are quite small at branchlets. New leaves of M. tetraphylla The leaves are sharp-tipped with some around 1.5cm. are bright in colour, whereas M. spikes along the margin, arranged in Photos: CSIRO Plant Industry integrifolia are light green. Nut-shells groups of three on the branchlets. are roughened the raw nut kernels New growth is pink-red and flowers have a slightly grey tint and sweeter are pinkish. flavour thanM. integrifolia nuts. Macadamia species in north Queensland Macadamia claudiensis Macadamia grandis Macadamia whelanii

Photo: B. Gray © Centre for Plant Photo: CSIRO Plant Industry Photo: J. Connors © Centre for Plant Research Biodiversity Research M. grandis is from the Cairns region and M. claudiensis is located in rainforests reaches 10–40m in height. The leaves are M. whelanii can be found in lowland of the region. in groups of four, with slightly wavy and coastal rainforest between Mount Leaves have smooth edges without margins without spikes. Flowers are Bellenden Ker to Mossman in Far North spikes and are in groups of five or six. -cream, and nuts are up to 7cm Queensland. Leaves are mainly in It grows to 25–30m in height and has wide including the outer shell. It is groups of five on the branchlets, and white flowers. The nuts including the unknown whether the nuts are toxic. are without spikes. Unlike M. tetraphylla outer shell are very large, up to 8cm and M. integrifolia, the yellow flowers wide, and do not have a bitter flavour grow upwards from the branch. The large like many other Macadamia species so nuts are around 5cm in diameter including may not be toxic. the outer shell and are slightly toxic.

 Queensland nut tree Macadamia integrifolia

Cultural heritage Macadamia, and belong to the same family. Macadamia nuts are of material and cultural importance to Aboriginal people. They are eaten whole or pressed to produce oil that is used as a liniment base or as a binder for ochres and clays used for face and body decoration and artwork. To crack the hard macadamia nut-shell, Aboriginal people used a base rock containing a groove to stop movement of the nut, placed a flat rock on top of the nut and used another “hammer” rock to hit the flat rock. This method causes less damage to the kernel than directly hitting the shell with a hammer or other implement. The first recorded cultivation of aMacadamia species was a M. integrifolia nut kernel planted in the Botanical Gardens in 1858 by the superintendent, Walter Hill. This tree continues to produce nuts and has a girth of around 2.5m at its base.

Conservation status M. integrifolia is listed as vulnerable under the Queensland Nature Conservation Act 1992 and the Commonwealth Environment Protection and Biodiversity Conservation Act 1999. Table 1 outlines the conservation status of the regional ecosystems (REs) with which M. integrifolia is associated.

Table 1. Regional ecosystems with which Macadamia integrifolia is associated and their status. RE Queensland Vegetation RE description *** Biodiversity Management Status * Status ** 12.3.1 Endangered Endangered Gallery rainforest/notophyll vine forest on alluvial plains 12.8.3 No concern at Not of concern Complex notophyll vine forest on present Cainozoic igneous rocks, altitude <600m 12.11.10 No concern at Not of concern Notophyll vine forest ± Araucaria present cunninghamii on metamorphics ± interbedded volcanics 12.12.16 No concern at Not of concern Notophyll vine forest on Mesozoic present to Proterozoic igneous rocks * Biodiversity Status as listed by the Environmental Protection Agency. ** Queensland Vegetation Management Act 1999 status as of December 2005. *** Refer to the Regional Ecosystem Description Database (REDD) at www.epa.qld.gov. au/nature_conservation/biodiversity/regional_ecosystems/ for full RE descriptions.

Threats to M. integrifolia Land clearing for agricultural and urban development is the greatest threat to M. integrifolia. South-east Queensland, particularly in coastal areas, has experienced the highest rate of population growth and associated development in Queensland. Other potential threats to M. integrifolia include wind, wildfire and inappropriate fire regimes.

Managing threats

Land clearing and vegetation management Naturally occurring Macadamia species are always associated with subtropical rainforest. Historical clearing of rainforest areas often spared M. integrifolia for the supply of edible nuts, resulting in the tree being isolated in the landscape. If there is no vegetation providing a protective windbreak around M. integrifolia strong winds can cause nut-laden branches to break or the entire tree to fall. Sites that are known to have populations of M. integrifolia need to be protected from clearing, and land managers should consider ways to permanently protect all or part of the property from future disturbance, for example under a nature refuge agreement.

 Queensland nut tree Macadamia integrifolia

If the land around an existing M. integrifolia has been cleared, there are several benefits Isolated Macadamia integrifolia from revegetating the area with subtropical rainforest species M. integrifolia is normally are susceptible to wind damage. associated with — recreating the natural environment will provide a more attractive landscape and a wind buffer for M. integrifolia; the increased diversity of vegetation will provide a refuge for wildlife, including native , spiders, snakes, lizards and frogs that provide natural control against pests such as mice, scarab beetle larvae, and grasshoppers; and soil will be less compacted allowing increased moisture penetration and cycling that may help to break down pesticides and organic refuse. It is also important to control weeds, for example lantana Lantana camara that forms dense thickets and camphor laurel Cinnamomum camphora that has an invasive root system, as they can dominate an area and have a detrimental effect on M. integrifolia as well as other native flora and fauna. Lantana can also promote the spread of fire into the area. The physical structure and bulk of lantana facilitates the generation of hotter fires and in dry times lantana drops its leaves, further increasing the ground fuel load. The Queensland Department of Natural Resources and Water has helpful information on weed management at their website http://www.nrw.qld.gov.au/pests/weeds/a_z_ listing.html, or telephone (07) 3405 5537 to obtain copies of their fact sheets.

Using buffers to protect M. integrifolia M. integrifolia needs well-drained soil. Vehicles and hoofed animals can compact the soil, restricting root growth and preventing water from penetrating and draining. To protect M. integrifolia a buffer should be created that excludes grazing animals and vehicles within at least a 5m radius of the species. If M. integrifolia is in an area where timber harvesting is planned, there must be a protective buffer of at least 3000sq.m (0.3ha) that excludes timber harvesting. All M. integrifolia should be at least 30m inside the protective buffer.

Managing fire To minimise the risk of a large destructive wildfire entering areas containing M. integrifolia land managers should conduct prescribed burns early in the dry season. Prescribed burning should retain a protective buffer of at least 30m around M. integrifolia. Fallen vegetation or timber debris that may present a significant fire fuel hazard should be removed from an area of 2m around the trunk of smaller M. integrifolia Macadamia integrifolia needs plants and up to 2m from the outer edge of the canopy of larger M. integrifolia . well-drained soil — avoid soil Land managers should consult with their local council or rural fire brigade www.( compaction by vehicles or stock. ruralfire.qld.gov.au) for further information about local requirements, restrictions and responsibilities with respect to prescribed burns and fire management.

 Queensland nut tree Macadamia integrifolia

Glossary Axil The upper angle between the leaf and the supporting stem or branch. Araucaria Flora belonging to the Araucaria, including Bunya pine and hoop pine. Argyrodendron Flora belonging to the genus Argyrodendron, including booyong and tulip oak. Branchlets Small, usually terminal, branches of a tree, plant or . Buffer An area of land that provides a protective barrier from unwanted impacts in an area beyond the buffer. Buttress roots Flat, plank-like expansions of the root and trunk at the base of a tree, often associated with shallow-rooted species such as rainforest trees. Complex notophyll vine forest A classification of Australian rainforest: complex relates to the complexity of the canopy structure; notophyll is the leaf length (7.5–12.5cm) of canopy trees; and vine forest relates to a large number of climbing vines greater than 9m in height. Endemic Found only in one particular area. Liniment A liquid rubbed onto the skin, usually to relieve stiffness or soothe pain. Nature refuges Privately owned land protected in perpetuity by conservation agreements between the landholders and the Queensland Government and declared nature refuges under the Nature Conservation Act 1992. Refer to www.epa.qld.gov.au/ naturerefuges for further information. Ochres Several types of natural earths mixed with oxides of , ranging in colour from pale yellow to and red. Racemes Clusters of flowers, where flowers with short stems are borne along a central stem/axis. Regional ecosystems (REs) The vegetation communities that are consistently associated with a particular combination of geology, landform and soil (see Sattler and Williams 1999), www.epa.qld.gov.au/nature_conservation/biodiversity/regional_ecosystems. Scree A steep mass of loose rock debris covering a slope or at the base of a cliff. Simple microphyll-notophyll vine forest A classification of Australian rainforest: simple relates to the complexity of the canopy structure; microphyll-notophyll is the leaf size (2.5–7.5cm and 7.5–12.5cm) of canopy trees; and vine forest relates to a large number of climbing vines greater than 9m in height. Simple notophyll vine forest A classification of Australian rainforest: simple relates to the complexity of the canopy structure; notophyll is the leaf size (7.5–12.5cm) of canopy trees; and vine forest relates to a large number of climbing vines greater than 9m in height.

Information sources Barry, S. and Thomas, G. (1994), Threatened vascular rainforest plants of south-east Queensland, Queensland Department of Environment and Heritage, pp. V38–V40. Brisbane Rainforest Action and Information Network, Rainforest plants, www.brisrain.webcentral.com.au/01_cms/details.asp?ID=9, 14 February 2006. Davidson, S. (2001), “Squirrelling the macadamia”, Ecos 107:5. Online, Australian Biological Resources Study, , http://www.deh.gov.au/biodiversity/abrs/online-resources/ flora/main/index.html, 6 March 2006. Francis, W.D. (1981), Australian rain-forest trees, Australian Government Publishing Service, Canberra. McConachie, I. The macadamia story, www.coopersnuthouse.com/maclib, 13 February 2006. Queensland Herbarium (1996), unpublished habitat notes from Queensland Herbarium specimen records of Macadamia integrifolia (1919- 1993), Environmental Protection Agency, Brisbane. Sattler, P. and Williams, R. (eds.) (1999), The conservation status of Queensland’s bioregional ecosystems, Environmental Protection Agency, Brisbane. Wrigley, J.W. and Fagg, M. (1989), Banksias, Waratahs and Grevilleas and all other plants in the Australian Proteaceae family, Collins Publishers Australia, NSW.

Primary author: S. Ryan, Queensland EPA Contact officer: Senior Conservation Officer, Completion date: November 2006 Ecosystem Conservation Branch, Reviewed: M. Powell, P. Forster, A. Borsboom Conservation Services Division, Published: Ecosystem Conservation Branch, EPA, [email protected] November 2006  00175-0607_Dec06